1. Field of the Invention
The present invention relates to a method for producing a semiconductor device.
2. Description of the Related Art
In recent years, there has been spreading a tendency towards downsizing of semiconductor devices and miniaturization of interconnects thereof that has been increasingly advancing. Thus, a greater number of I/O pads and vias are required to be arranged in a narrow semiconductor chip region (a region of a semiconductor substrate that overlaps semiconductor chips when the chips are seen through in planar view). Simultaneously, the density of pins therein is also increasing. Furthermore, in a ball grid array (BGA) package, many terminals are formed in its semiconductor chip region, so that its region where other elements are to be formed is restricted. Thus, a method of drawing out, on a semiconductor package substrate, wires from terminals in a region outside the chip region is adopted.
Under such a situation, if appropriate measures are taken case by case for the downsizing of semiconductor devices and miniaturization of interconnects thereof, the production efficiency is reduced because of the extension of production lines, an increase in the complexity of the production process, and the like. Thus, such measures cannot fulfill a requirement of cost reduction.
To address this, in order to reduce costs for the production of a semiconductor package, a method of arranging plural chips, which have been made into individual pieces, on a support, and sealing the chips all together with a resin to form a package is suggested. For example, U.S. Pat. No. 7,202,107 discloses a method of arranging plural chips, which have been made into individual pieces, on a thermosensitive adhesive formed on a support, forming a common carrier made of plastic material to cover the chips and the thermosensitive adhesive, and then peeling the common carrier in which the chips are buried and the thermosensitive adhesive from each other by heating.
However, in the method for producing a semiconductor device according to U.S. Pat. No. 7,202,107, the thermosensitive adhesive is used to form the common carrier. Thus, the adhesive imposes a limitation to high-temperature treatment. Furthermore, a cycle of heating and heat-dissipation is necessary. In light of these matters, there remains room for improvement from the viewpoint of the production efficiency of semiconductor devices, and the flexibility of the production design thereof.